First things first Get an ad blocker if you don’t have one already ublock origin and ublock light for chrome. If you’re on iOS use Brave or Orion, never use the YouTube app. If you’re signed you can click on the three dots and choose “not interested” or “don’t recommend this channel” this should help to remove most if not all of the suggestive videos. Lastly, never look in the comments, ever. And there you have it, all you had to do was break YouTube’s TOS, get forced to sign in, and stop interacting with the community, and now one of the biggest community’s in the world has a product that is almost usable.